More recently, auxiliary autotransfusion blood collection containers have been employed with chest drainage units which employ suction during fluid collection and which permit reinfusion of the collected blood to the patient thereby avoiding the necessity of infusing stored blood from another person and the possibility of transmitting a disease to the patient.
Some autotransfusion devices of this type have had certain problems or disadvantages associated with them. A blood collection container or bottle which is non-collapsible has been connected to a chest drainage unit such that suction is applied through the container to the mediastinal or plueral cavity of a patient with the container receiving drainage blood. In order to reinfuse the blood into the patient from the non-collapsible container however, the bottle must be vented to atmosphere to allow the collected blood to flow from such container to the patient. In such a case, air is in contact with the blood and may affect its characteristics. Also, an air filter must be used to filter air from the atmosphere into the container during infusion.
Collapsible blood collection containers such a collapsible bags have been used in order to avoid the necessity and problems of venting the container during reinfusion. However, such collapsible bag containers have also had certain problems and disadvantages. For example, the collapsible bag requires apparatus to maintain the bag in an expanded condition during blood collection in spite of the negative pressures or suction forces within the bag. In general, this has caused the bag and the bag expanding device to be relatively complicated and expensive. In some cases, the bags, when expanded, took on indefinite shapes which produced indefinite volumes and thus provided inaccurate or unreliable indications of the amount of blood collected at any time.